Remains of an old ship The Griffin found in Lake Michigan

At the bottom of Lake Michigan, an exploration team found the remains of an old ship called the Griffin.

The Griffin is thought to be the first ship of European design to sail the upper Great Lakes. The ship was commanded by a 17th century French explorer.

"This is definitely the Griffin — I'm 99.9 percent sure it is," said Steve Libert, according to Associated Press. "This is the real deal."

Wood particles were found including timber that was part of the bowsprit of Rene-Robert Cavelier, Sieur de La Salle’s ship. Experts say that the Griffin disappeared along with six crew members on its maiden voyage in 1679.

Some are doubting, though, that this is the actual ship.

“I wish so much for him to have discovered it ... but there’s so little hard information,” said Rick Mixter, a video producer who has visited 150 shipwrecks, according to The Detroit News.

Search teams are hoping to excavate further. They plan to seek state and federal permits in September.